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Fat Guy

Thermometer trust issues

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I was re-reading Daniel Patterson's excellent essay from Food & Wine magazine, "Do Recipes Make You a Better Cook?," and I was reminded that, in that essay, Patterson said one of the smartest things to be said about food last year:

telling someone to cook a piece of fish for exactly five minutes is like saying, "Drive for exactly five minutes and then turn right." Sometimes you'd hit the road, other times the side of a building.

When you're cooking thin fish fillets in a skillet or under the broiler, there's really no objective measure that can be applied. You need to be able to figure out doneness by examining a variety of other factors. Time is relevant, but only as a rough guideline to help you know when to start collecting other information.

But when it comes to cooking bigger pieces of meat, things change, because we have thermometers to work with. Because Patterson is trying to make a certain point, he doesn't even mention the existence of thermometers. Yet a thermometer is the key to accurate meat cookery. Veteran cooks can talk all they want about how they can judge doneness by pressing on a piece of meat, but that's never going to be as accurate as a thermometer.

Still, thermometers aren't foolproof. In many ways, it takes more skill to use a thermometer than it does to press on meat. Here are a few issues that arise:

- Thermometer placement is the big one. You can only measure whatever the thermometer is touching. So if you don't get it placed dead center in your roast, you're not going to be taking the correct reading. This is especially problematic with irregular items like whole birds. You can't just plunge it in anywhere, unless you're doing certain types of slow cooking where the idea is to get the whole product to a uniform temperature.

- There are variations in the way individual thermometers behave, especially at the consumer level. While expensive professional thermocouple thermometers tend to be both accurate and precise, consumer thermometers are often neither. Also, different thermometers have different properties in terms of what part of the thermometer's probe is taking the actual reading: just the very tip, the first half inch, the first inch.

- In some situations there are bleed-through effects from a grill, a broiler or a burner. So the temperature the thermometer shows is altered by factors other than the temperature of what you're actually trying to measure.

I mean, when I go over to a friend's house and we do something like cook a roast, I look at that thermometer and I just don't trust it. I think, oh man, it says 140 but we're going to pull this thing out and it's going to be totally different.

Those of you who are fans of thermometers: how do you address those issues in order to achieve a high level of confidence in your thermometers? What other issues come up, and how do you address those?


Steven A. Shaw aka "Fat Guy"
Co-founder, Society for Culinary Arts & Letters, sshaw@egstaff.org
Proud signatory to the eG Ethics code
Director, New Media Studies, International Culinary Center (take my food-blogging course)

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I bought a dual-thermocouple meter (an Extech model recommended by nathanm over on the sous vide thread) and a miniature needle probe (also recommended by nathanm).

I got them mainly because I wanted to have a way of measuring the internal temp of foods inside the sous vide bag. The miniature probe is small enough and sharp enough to penetrate the bag without too much damage. A bit of weatherstripping tape seals the hole and keeps the bag from leaking.

Anyways, since I have the meter, I find myself using it for much more than just sous vide. It's great for monitoring a large roast or such. I stick the needle probe in the roast (or turkey, or whatever), and run a second bare-wire probe into the oven. That way I don't have to rely on the notoriously inaccurate temperature settings on the oven dial.

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I don't think I ever trust the thermometer as a stand-alone indication of doneness. I like to have time/appearance backups too. I like to use a thermometer to confirm what I already suspect. Does that make sense?


Anna Nielsen aka "Anna N"

...I just let people know about something I made for supper that they might enjoy, too. That's all it is. (Nigel Slater)

"Cooking is about doing the best with what you have . . . and succeeding." John Thorne

Our 2012 (Kerry Beal and me) Blog

My 2004 eG Blog

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I'm trying to cultivate the habit of using as many cues as possible simultaneously. It's easy to get in the habit of just using one (visual, feel, time, thermometer, etc.).

The nice thing about using several, beyond getting multiple opinions, is that you get to learn more about what each cue really indicates. You start to get a sense of how something feels when the center is 140 degrees, and how long it takes for that cut of meat at that size to get to that temp, etc.

You also get a better sense of when one of your indicators isn't trustworthy. For example, when I was experimenting with roasting chickens, I used a probe thermometer (placed in the section between breast and thigh) to monitor doneness. I became a slave to the thermometer, and didn't pay attention to other signs. A couple of times, the reading was way off, and I ended up pulling the bird out ten degrees over- or undercooked. It turns out that with a chicken, thermometer placement is really tricky, and there can be a range of over ten degrees between the thermometer tip being in flesh, in an air pocket, or against a bone. This issue is separate from the accuracy of the thermometer, which is pretty good ... it's more along the lines of the difficulties with using them that you mentioned.

Now i might use a thermometer, especially in an unfamiliar oven, but I don't obey it without looking at other indicators, like surface browning and the looseness of the hip joint.


Edited by paulraphael (log)

Notes from the underbelly

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This is slightly OT, but if someone could recommend a good and fast (!!) thermometer and a website that sells them, I would be grateful.

I'm looking for something to use quickly when cooking on the stove top, with a needle probe to check for doneness. Is that steak really medium rare, is that potato perfect in the center etc.

I have a digital thermometer with a separate probe to use in the oven and I also have a pen-type thermometer from Williams-Sonoma, but that one is just too slow.

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This is slightly OT, but if someone could recommend a good and fast (!!) thermometer and a website that sells them, I would be grateful.

I'm looking for something to use quickly when cooking on the stove top, with a needle probe to check for doneness. Is that steak really medium rare, is that potato perfect in the center etc.

I have a digital thermometer with a separate probe to use in the oven and I also have a pen-type thermometer from Williams-Sonoma, but that one is just too slow.

Hi,

You will want a thermapen. It's fast, reliable and expensive.

ThemoWorks Thermapen

Tim

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This is slightly OT, but if someone could recommend a good and fast (!!) thermometer and a website that sells them, I would be grateful.

Sounds like you need a Thermapen!

I've had the original model for a few years now, and I would definitely recommend it -- it overcomes many of the issues brought up by FG, in that its speed makes it so easy to take multiple readings. For example, I can check the temp on a roast chicken in about 7 seconds: poke the thigh, breast, etc. and the temp of each of those spots QUICKLY registers on the Thermapen. The thin profile of the probe also causes little damage to the item in question.

http://www.thermoworks.com/


So we finish the eighteenth and he's gonna stiff me. And I say, "Hey, Lama, hey, how about a little something, you know, for the effort, you know." And he says, "Oh, uh, there won't be any money. But when you die, on your deathbed, you will receive total consciousness."

So I got that goin' for me, which is nice.

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This is slightly OT, but if someone could recommend a good and fast (!!) thermometer and a website that sells them, I would be grateful.

I'm looking for something to use quickly when cooking on the stove top, with a needle probe to check for doneness. ...

You will want a thermapen. It's fast, reliable and expensive.

ThemoWorks Thermapen

Specifically, I believe you want the *FR* version of the Thermapen, and, there are two versions covering different ranges

And you need to choose F or C...


"If you wish to make an apple pie from scratch ... you must first invent the universe." - Carl Sagan

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I like the looks of the plug-mount Thermapen where you can use different probes.


--

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This is slightly OT, but if someone could recommend a good and fast (!!) thermometer and a website that sells them, I would be grateful.

I'm looking for something to use quickly when cooking on the stove top, with a needle probe to check for doneness. Is that steak really medium rare, is that potato perfect in the center etc.

I have a digital thermometer with a separate probe to use in the oven and I also have a pen-type thermometer from Williams-Sonoma, but that one is just too slow.

Hi,

You will want a thermapen. It's fast, reliable and expensive.

ThemoWorks Thermapen

Tim

You really don't need an $89 "fast reading"thermometer, just put it on something hot before you check what you want to test. You know aprox.º where it will be , so heat it up to near that temp and it will respond as fast as the $89 unit for lots less....

Bud

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And if I'm deep frying or making candy, I should "preheat" my cheap thermometer so it's in the corresponding temp neighborhood? No thanks, I'll stick with my Thermapen...


So we finish the eighteenth and he's gonna stiff me. And I say, "Hey, Lama, hey, how about a little something, you know, for the effort, you know." And he says, "Oh, uh, there won't be any money. But when you die, on your deathbed, you will receive total consciousness."

So I got that goin' for me, which is nice.

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I mean, when I go over to a friend's house and we do something like cook a roast, I look at that thermometer and I just don't trust it. I think, oh man, it says 140 but we're going to pull this thing out and it's going to be totally different.

I bring my own. Next to my knife and comprehensive medical plan my thermometer sees a lot of action.

People think I can cook because I have a thermometer that looks like a pen. Pfft, "victims". :cool:


"And in the meantime, listen to your appetite and play with your food."

Alton Brown, Good Eats

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Are the best meat thermometers ones you use as needed with a needle and a quick readout that do not stay in the roast? I take it both versions of the Thermapen described upthread work that way--you just do it quick as the end is near....Are there any that stay in during the entire cooking process?

I've got a handle on steaks; I have finally learned to trust the palm pressing method, which did take some practice. For roast chicken I have my own method: when my husband says "take it out" I know it needs another 15 minutes! If you don't have my husband, the shake-a-leg method works in a pinch. But when it comes to a big hunk of meat like a rib roast I'm just clueless. I don't make them because I'm too scared of spending the big bucks only to have overdone meat. Maybe I could work up the nerve if I was slinging a Thermapen?

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For what it is worth, I calibrate my thermometers by testing in boiling water. Don't know how valid this is - but it makes me happy.

Enjoying the reparte.

Jmahl


The Philip Mahl Community teaching kitchen is now open. Check it out. "Philip Mahl Memorial Kitchen" on Facebook. Website coming soon.

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Everyone says that the thermapen is very "fast". Does this mean it is fast in coming up to the temperature of the food because the tip is thin or does this mean the sampling rate is fast so you can see the numbers changing quickly?

I have a 5 year old leave-in probe thermometer that is accurate (tested in ice water and boiling water) but it is so damn slow! The thermometer only seems to take a sample every 4 seconds. Oil for example can jump many degrees in that period on a high power burner.

Can anyone recommend a leave-in thermometer with an oven proof lead that has a fast sampling rate? Something better than once a second?

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The Thermapen certainly looks like a nice item, and the new models (3 and 7) accept oven probes -- they accept any type K thermocouple probe. But you're talking about a significant expenditure: $80 or more for the thermometer, plus $30 or more for the oven probe, plus whatever other probes you buy at $24 - $80 each. And the Thermapen isn't even switchable between F and C -- you have to choose one or the other forever when you buy it.

So the question for me becomes what does a Thermapen do to address the issues that concern me better than the relatively cheap thermometers I already have? I have a $25 Polder thermometer with an oven probe (it switches between F and C, and it even has a timer) and a few non-electronic thermometers (instant-read, deep-frying/candy, etc.) that couldn't have cost more than $6 or so each. I'm sure they're neither as fast, accurate nor precise as a Thermapen, but they work.

The problem is that they don't automatically place themselves in the exact right spot on a turkey, they have quirks in terms of what part of the thermometer actually takes the reading, and they don't work very well on, for example, a charcoal grill because the heat of the grill throws off the readings. Does a Thermapen address those issues? It seems to me that you can easily spend hundreds of dollars on a professional-level thermometer kit but it's not going to do an appreciably better job than a cheap thermometer unless you solve a number of other problems first.


Steven A. Shaw aka "Fat Guy"
Co-founder, Society for Culinary Arts & Letters, sshaw@egstaff.org
Proud signatory to the eG Ethics code
Director, New Media Studies, International Culinary Center (take my food-blogging course)

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One thing I've never seen mentioned about probe thermometers is that often the probe acts as an excellent conductor and will heat up the meat immediately adjacent to it and give spurious readings. I got sick of seeing underdone meat so my new procedure is to now stick a thermometer 3/4 of the way to the centre of the meat, wait until it comes to temp and then push it in a further 1/4 of the way and watch the reading drop a good 10F and let it come up to temp again.


PS: I am a guy.

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I've found that my probe works best if I insert it towards the end of cooking. I think that's because of the heat conductivity that Shalmanese mentioned.

For most items, I feel that I can hit center mass most of the time and I haven't had too many issues. Turkey's and chickens are the things that can throw me. It's hard to tell how far the probe has gone, and you have little to no visual reference of where a bone might be. One way to get around this might be to get one of the Polder thermometers that accepts two probes. Then you can have a probe in two different portions of the bird.

You can also test the probe for accuracy by placing it boiling water, it should be 212 degrees. You can then mix crushed ice with water in a glass and take them temp, after it has sat for several minutes. The probe should read 32 degrees. Just make sure the probe isn't touching the ice.

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. . .

You can also test the probe for accuracy by placing it boiling water, it should be 212 degrees. You can then mix crushed ice with water in a glass and take them temp, after it has sat for several minutes. The probe should read 32 degrees. Just make sure the probe isn't touching the ice.

But only at sea level! It is surprising if you look it up how a few hundred feet will throw off the boiling point. You don't have to live in Denver!


Anna Nielsen aka "Anna N"

...I just let people know about something I made for supper that they might enjoy, too. That's all it is. (Nigel Slater)

"Cooking is about doing the best with what you have . . . and succeeding." John Thorne

Our 2012 (Kerry Beal and me) Blog

My 2004 eG Blog

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Are the best meat thermometers ones you use as needed with a needle and a quick readout that do not stay in the roast? I take it both versions of the Thermapen described upthread work that way--you just do it quick as the end is near....Are there any that stay in during the entire cooking process?

...

Maybe I could work up the nerve if I was slinging a Thermapen?

The main selling point of the Thermapen is that it is fast. It is also accurate, but that is really secondary since any decent digital thermometer will be accurate enough for most cooking application.

Since it is fast, you can take spot reading on the fly which is very useful when you are cooking on the top of the stove or if you want to check specific parts (ie the breast of a turkey).

When cooking in the oven I belive an ordinary digital probe thermometer (USD 10-20) will be just as good. Stick the probe in the meat, set the alarm and then put everything in the oven. Heat build up will be gradual so speed won't be a problem. If you check your thermometer beforehand with boiling water and melting ice as described above, accuracy won't be a problem either.

The ideal combination is probably one of each.

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...  and a few non-electronic thermometers (instant-read, deep-frying/candy, etc.) that couldn't have cost more than $6 or so each. I'm sure they're neither as fast, accurate nor precise as a Thermapen, but they work.

Um... "work"?

If you actually have a tool that delivers enough precision. sufficient accuracy and does it quickly enough for your needs, then it 'works' for you.

But if the tool is not capable of delivering your requirements, then does it really "work" ?

The problem is that they don't automatically place themselves in the exact right spot on a turkey, they have quirks in terms of what part of the thermometer actually takes the reading, and they don't work very well on, for example, a charcoal grill because the heat of the grill throws off the readings. ...

Thing is, with a virtually instant readout, you can take measurements in lots of different places, so that you can, with practice, develop the skill of going straight for the critical coldest spot. As well as seeing the maximum...

I think that generally it'd make sense to move things to the side of a charcoal grill (or out from under a salamander) before 'probing' it (no claim here to asbestos fingers!)

I don't have a Thermapen - but I'm fairly sure its a matter of "not yet".


"If you wish to make an apple pie from scratch ... you must first invent the universe." - Carl Sagan

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Thing is, with a virtually instant readout, you can take measurements in lots of different places, so that you can, with practice, develop the skill of going straight for the critical coldest spot. As well as seeing the maximum...

If you want to poke the thing you're cooking five times while standing there with the oven door open, I suppose you can take a bunch of measurements for practice, but then again you can do this with a cheap instant-read thermometer too -- it will just take a little longer. I'd be interested to know how much longer. If it's, for example, 30 seconds v. 1 minute to take 5 readings then that doesn't seem like a big deal. I guess the Thermapen has a thinner probe.

This does introduce an idea, though. For just a few dollars (significantly less than the cost of a Thermapen, no less the two Thermapens I'd need in order to read F and C) I could buy a couple of cheapo supermarket chickens, stick them in the oven and use them for practice, poking and prodding them all over to take temperatures. Since I'd not be serving them whole (I'd probably make sandwiches or chicken salad from the mangled meat), I could really get in there and experiment. Hmm.


Steven A. Shaw aka "Fat Guy"
Co-founder, Society for Culinary Arts & Letters, sshaw@egstaff.org
Proud signatory to the eG Ethics code
Director, New Media Studies, International Culinary Center (take my food-blogging course)

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My experience with cheap thermometers is that they take 20-30 seconds to get an accurate reading. Subsequent readings will probably be faster since the probe is already hot.


Edited by TheSwede (log)

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One aspect of the thermometer question that we have not yet touched on - oven thermometers.

Although I have an excellent, fairly new Wolf electric oven which appears to reach the set temperature without problem I do not feel comfortable if I do not have a separate oven thermometer. The classic Taylor is 100% reliable but almost impossible to read without opening the oven door. I also have a digital oven thermometer which carries the Williams Sonoma label. This sits outside the oven and the sensor clips onto an oven rack. It is perfectly reliable except when I am using convection when it goes totally crazy. Does anyone know of an oven thermometer that is both easy to read and works as well with convection as with conventional heat?


Ruth Friedman

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